Optical Data Communication System and Associated Method

ABSTRACT

An optical data communication system includes a plurality of resonator structures and a laser array that includes a plurality of lasers optically connected to the plurality of resonator structures. Each resonator structure has a respective free spectral wavelength range and a respective resonance wavelength. A maximum difference in resonance wavelength between any two resonator structures in the plurality of resonator structures is less than a minimum free spectral wavelength range of any resonator structure in the plurality of resonator structures. Each laser in the plurality of lasers is configured to generate continuous wave light having a respective wavelength. The laser array has a central wavelength. A variability of the central wavelength is greater than a minimum difference in resonance wavelength between any two spectrally neighboring resonator structures in the plurality of resonator structures.

CLAIM OF PRIORITY

This application claims priority under 35 U.S.C. 119(e) to U.S.Provisional Patent Application No. 63/074,394, filed on Sep. 3, 2020,the disclosure of which is incorporated herein by reference in itsentirety for all purposes.

BACKGROUND 1. Field of the Invention

The present invention relates to optical data communication.

2. Description of the Related Art

Optical data communication systems operate by modulating laser light toencode digital data patterns. The modulated laser light is transmittedthrough an optical data network from a sending node to a receiving node.The modulated laser light having arrived at the receiving node isde-modulated to obtain the original digital data patterns. Therefore,implementation and operation of optical data communication systems isdependent upon having reliable and efficient devices for modulatingoptical signals and for receiving optical signals. It is within thiscontext that the present invention arises.

SUMMARY

In an example embodiment, an optical data communication system isdisclosed. The optical data communication system includes a plurality ofresonator structures. Each resonator structure in the plurality ofresonator structures has a respective free spectral wavelength range anda respective resonance wavelength. A maximum difference in resonancewavelength between any two resonator structures in the plurality ofresonator structures is less than a minimum free spectral wavelengthrange of any resonator structure in the plurality of resonatorstructures. The optical data communication system also includes a laserarray that includes a plurality of lasers optically connected to theplurality of resonator structures. Each laser in the plurality of lasersis configured to generate continuous wave light having a respectivewavelength. The laser array has a central wavelength. A variability ofthe central wavelength is greater than a minimum difference in resonancewavelength between any two spectrally neighboring resonator structuresin the plurality of resonator structures.

In an example embodiment, a method is disclosed for configuring anoptical data communication system. The method includes having aelectronic/photonic device for optical data communication that includesa plurality of resonator structures. Each resonator structure in theplurality of resonator structures has a respective free spectralwavelength range and a respective resonance wavelength. A maximumdifference in resonance wavelength between any two resonator structuresin the plurality of resonator structures is less than a minimum freespectral wavelength range of any resonator structure in the plurality ofresonator structures. The method also includes optically connecting alaser array to the electronic/photonic device. The laser array includesa plurality of lasers optically connected to the plurality of resonatorstructures. Each laser in the plurality of lasers is configured togenerate continuous wave light having a respective wavelength. The laserarray has a central wavelength. A variability of the central wavelengthis greater than a minimum difference in resonance wavelength between anytwo spectrally neighboring resonator structures in the plurality ofresonator structures.

Other aspects and advantages of the disclosed embodiments will becomemore apparent from the following detailed description, taken inconjunction with the accompanying drawings, illustrating by way ofexample the disclosed embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows an example of a remote optical power supply for an opticaldata communication system in which a laser array and an opticaldistribution network are used to provide multiple wavelengths of CWlaser light on each of multiple optical fibers, in accordance with someembodiments.

FIG. 1B shows a diagram indicating how each of the optical fibersreceives each of the multiple wavelengths of CW laser light at asubstantially equal intensity (power), in accordance with someembodiments.

FIG. 1C shows an example diagram of the CMOS/SOI photonic/electronicchip, in accordance with some embodiments.

FIG. 2 shows a transmission spectrum of a given resonator structure ofthe plurality of resonator structures, in accordance with someembodiments.

FIG. 3 shows how the plurality of resonator structures are configured sothat each resonator structure in the plurality of resonator structureshas a different resonance wavelength relative to the other resonatorstructures in the plurality of resonator structures, in accordance withsome embodiments.

FIG. 4A shows an example transmission spectrum for a set of fourresonator structures, and a spectral positioning of wavelengths ofcontinuous wave laser light as generated by the laser array relative tothe resonance wavelengths of the set of four resonator structures, inaccordance with some embodiments.

FIG. 4B shows the spectral positioning of wavelengths of continuous wavelaser light as generated by the laser array to the resonance wavelengthsof the set of four resonator structures when the central wavelength ofthe laser array is at a low end of the allowable variability, inaccordance with some embodiments.

FIG. 4C shows the spectral positioning of wavelengths of continuous wavelaser light as generated by the laser array to the resonance wavelengthsof the set of four resonator structures when the central wavelength ofthe laser array is at a high end of the allowable variability, inaccordance with some embodiments.

FIG. 5 shows a flowchart of a method for configuring an optical datacommunication system, in accordance with some embodiments.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth inorder to provide an understanding of the present invention. It will beapparent, however, to one skilled in the art that the present inventionmay be practiced without some or all of these specific details. In otherinstances, well known process operations have not been described indetail in order not to unnecessarily obscure the present invention.

In optical data communication applications, high bandwidth,multi-wavelength WDM (Wavelength-Division Multiplexing) systems arenecessary to meet the needs of increasing interconnect bandwidthrequirements. In some implementations of these WDM systems, a remotelaser array is configured to generate multiple wavelengths of continuouswave (CW) laser light which are combined through an optical distributionnetwork to provide multiple wavelengths of laser light to each of manyoptical ports. The multiple wavelengths of laser light are transmittedfrom any one or more of the optical ports to a CMOS (ComplementaryMetal-Oxide-Semiconductor) or SOI (silicon-on-insulator)photonic/electronic chip that sends and receives data in an optical datacommunication system. In some implementations, a multi-wavelength laserlight source includes an array of lasers that have outputs opticallyconnected to respective optical inputs of an optical distributionnetwork, e.g., optical multiplexer, that routes each incoming wavelengthof CW laser light to each of multiple optical output ports of theoptical distribution network. The multiple wavelengths of CW laser lightare then routed from a given optical output port of the opticaldistribution network to a given optical input port of the CMOS/SOIphotonic/electronic chip, such as the TeraPHY™ chip produced by AyarLabs, Inc.

FIG. 1A shows an example of a remote optical power supply 100 for anoptical data communication system in which a laser array 103 and anoptical distribution network 105 are used to provide multiplewavelengths of CW laser light on each of multiple optical fibers 107, inaccordance with some embodiments. The laser array 103 includes multiplelaser elements 103-1 through 103-N, with each of the multiple laserelements 103-1 through 103-N operating to generate laser light at adifferent one of N wavelengths. The optical distribution network 105routes the laser light at each of the N wavelengths, as generated by themultiple laser elements 103-1 through 103-N, to each of a number (M) ofoptical output ports 108. In some embodiments, the N multiplewavelengths of laser light that are provided to a given one of the Moptical output ports 108 are transmitted directly into a correspondingone of the optical fibers 107. In some embodiments, the N multiplewavelengths of laser light that are provided to a given one of the Moptical output ports 108 are transmitted through an optical amplifier109 and then into a corresponding one of the optical fibers 107.

FIG. 1B shows a diagram indicating how each of the optical fibers 107receives each of the multiple wavelengths of CW laser light at asubstantially equal intensity (power), in accordance with someembodiments. Each of the optical fibers 107 can be connected to routethe multiple wavelengths of CW laser light that it receives from theremote optical power supply 100 to a corresponding optical port on aCMOS/SOI photonic/electronic chip 111.

FIG. 1C shows an example diagram of the CMOS/SOI photonic/electronicchip (“chip” hereafter) 111, in accordance with some embodiments. Thechip 111 includes a number M of transmit macros 115-1 through 115-M, anda number M of receive macros 127-1 through 127-M. Each transmit macro115-1 through 115-M includes an optical input port 117-1 through 117-M,respectively, that is connected to a corresponding one of the opticalfibers 107-1 through 107-M, respectively, to receive themulti-wavelength CW laser light from the remote optical power supply100. In some embodiments, the number M of optical fibers 107-1 through107-M required from the remote optical power supply 100 equals thenumber of optical input ports 117-1 through 117-M of the transmit macros115-1 through 115-M of the chip 111.

The optical input ports 117-1 through 117-M are optically connected tooptical waveguides 121-1 through 121-M, respectively. Each of theoptical waveguides 121-1 through 121-M extends past a plurality ofresonator structures 119-x-y, e.g., microring resonator structures119-x-y, where (x) is the transmit macro number and (y) designates aparticular one of the multiple wavelengths of CW laser light. In someembodiments, the plurality of resonator structures 119-x-y is configuredas a plurality of optical microring modulators 119-x-y. In someembodiments, each of the plurality of resonator structures 119-x-y is amicroring resonator having an outer diameter of less than 10micrometers. In various embodiments, each of the plurality of resonatorstructures 119-x-y is defined as a circuitous waveguide structure thathas essentially any shape and/or size that is compatible with thefunctionality of the corresponding transmit macro x and chip 111. Forexample, in some embodiments, one or more of the plurality of resonatorstructures 119-x-y is configured as a ring-shaped resonator structurehaving a annular ring shape cross-section. In some embodiments, one ormore of the plurality of resonator structures 119-x-y is configured as adisc-shaped resonator structure having a disc shape cross-section. Insome embodiments, one or more of the plurality of resonator structures119-x-y is configured to have a cross-sectional shape that is neitherring-shaped nor disc-shaped, but that is circuitous. In someembodiments, each resonator structure in the plurality of resonatorstructures 119-x-y is configured to have a substantially same shape andsize. In some embodiments, each resonator structure in the plurality ofresonator structures 119-x-y is configured to have shape and/or sizethat is within +/−20% of the shape and/or size of one or more others ofplurality of resonator structures 119-x-y. In some embodiments, thedifferent resonator structures in the plurality of resonator structures119-x-y are configured to have different shapes, different sizes, orboth different shapes and different sizes. Regardless of the specificshape and size of the plurality of resonator structures 119-x-y, itshould be understood that each of the plurality of resonator structures119-x-y is shaped and sized to have a respective resonance wavelength(y), such that light of the respective resonance wavelength (y) willoptically couple into a mode of the resonator structure 119-x-y havingthe respective resonance wavelength (y).

After extending past each of the plurality of resonator structures119-x-y, each of the optical waveguides 121-1 through 121-M extends to arespective optical output port 123-1 through 123-M. In the example ofFIG. 1C, each of the plurality of resonator structures 119-x-y functionsto modulate the incoming CW laser light of the corresponding wavelength(y) in accordance with electrical signals that represent digital data soas to generate modulated light of the corresponding wavelength (y) thathas a modulation pattern that conveys the digital data represented bythe electrical signals. The modulated light is transmitted from theoptical output ports 123-1 through 123-M into respective optical fibers124-1 through 124-M that carry the modulated light to a destinationsomewhere within the optical data communication system.

In some embodiments, each of the plurality of resonator structures119-x-y is tunable to operate at a specified wavelength of light. Also,in some embodiments, the specified wavelength of light at which a givenone of the plurality of resonator structures 119-x-y is tuned to operateis different than the specified wavelengths at which the others of theplurality of resonator structures 119-x-y are tuned to operate. In someembodiments, corresponding heating devices 120-x-y are respectivelypositioned near the plurality of resonator structures 119-x-y to providefor thermal tuning of the resonant wavelength of the plurality ofresonator structures 119-x-y. In some embodiments, a correspondingheating device 120-x-y is positioned within an inner regioncircumscribed by a given resonator structure 119-x-y to provide forthermal tuning of the resonant wavelength of the given resonatorstructure 119-x-y. In some embodiments, the heating devices 120-x-y ofthe plurality of resonator structures 119-x-y are connected tocorresponding electrical control circuitry within the correspondingtransmit (Tx) slice that is operated to independently and separatelythermally tune the resonant wavelengths of the plurality of resonatorstructures 119-x-y. In some embodiments, each of the plurality ofresonator structures 119-x-y is connected to corresponding electricaltuning circuitry within the corresponding transmit (Tx) slice that isoperated to electrically tune the resonant wavelength of the resonatorstructure 119-x-y. In various embodiments, each of the plurality ofresonator structures 119-x-y operates as part of an optical modulatorand/or optical multiplexer.

It should be understood that in some embodiments the optical input ports117-1 through 117-M and the optical output ports 123-1 through 123-M areoperated in a reverse manner, such that the ports 117-1 through 117-Moperate as optical output ports instead of optical input ports, and suchthat the ports 123-1 through 123-M operate as optical input portsinstead of optical output ports. In these embodiments, the opticalfibers 107-1 through 107-M are connected to convey CW laser light fromthe optical power supply 100 to the ports 123-1 through 123-M, and theoptical fibers 124-1 through 124-M are connected to convey modulatedlight from the ports 117-1 through 117-M to destinations within theoptical data communication system.

Each receive macro 127-1 through 127-M includes an optical input port125-1 through 125-M, respectively, that is optically connected to acorresponding one of optical fibers 126-1 through 126-M, respectively,to receive modulated light of various wavelengths from other deviceswithin the optical data communication system. The optical input ports125-1 through 125-M are connected to optical waveguides 128-1 through128-M, respectively. Each of the optical waveguides 128-1 through 128-Mextends past a plurality of resonator structures 129-x-y, e.g.,microring resonator structures 129-x-y, where (x) is the receive macronumber and (y) designates a particular one of the multiple wavelengthsof light. In some embodiments, each of the plurality of resonatorstructures 129-x-y is a microring resonator having an outer diameter ofless than 10 micrometers. In the example of FIG. 1C, the plurality ofresonator structures 129-x-y is configured as a plurality of opticalmicroring detectors 129-x-y. Each of the optical microring detectors129-x-y functions to detect incoming light of a particular wavelength(y) and convert the incoming light into electrical signals in accordancewith the modulation pattern of the incoming light, so that theelectrical signals can be processed by circuitry to recreate the digitaldata upon which the incoming modulated light was modulated. The chip 111includes various electronics circuitry 131 formed using CMOS processes.It should be understood that the electronic circuitry of the chip 111provides for control and operation of the plurality of resonatorstructures 119-x-y and the plurality of resonator structures 129-x-y.

In some embodiments, each of the plurality of resonator structures129-x-y is tunable to operate at a specified wavelength of light. Also,in some embodiments, the specified wavelength of light at which a givenone of the plurality of resonator structures 129-x-y is tuned to operateis different than the specified wavelengths at which the others of theplurality of resonator structures 129-x-y are tuned to operate. In someembodiments, corresponding heating devices 130-x-y are respectivelypositioned near the plurality of resonator structures 129-x-y to providefor thermal tuning of the resonant wavelength of the plurality ofresonator structures 129-x-y. In some embodiments, a correspondingheating device 130-x-y is positioned within an inner regioncircumscribed by a given resonator structure 129-x-y to provide forthermal tuning of the resonant wavelength of the given resonatorstructure 129-x-y. In some embodiments, the heating devices 130-x-y ofthe plurality of resonator structures 129-x-y are connected tocorresponding electrical control circuitry within the correspondingreceive (Rx) slice that is operated to independently and separatelythermally tune the resonant wavelengths of the plurality of resonatorstructures 129-x-y. In some embodiments, each of the plurality ofresonator structures 129-x-y is connected to corresponding electricaltuning circuitry within the corresponding receive (Rx) slice that isoperated to electrically tune the resonant wavelength of the resonatorstructure 129-x-y. In various embodiments, each of the plurality ofresonator structures 129-x-y operates as part of a photodetector and/oroptical demultiplexer.

In some embodiments, the laser array 103 is physically separate from adevice, e.g., chip 111, that includes the plurality of resonatorstructures 119-x-y. It should be understood that the configuration ofthe remote optical power supply 100 as shown in FIG. 1A is provided byway of example. In various embodiments, the configuration of the remoteoptical power supply 100 can vary from what is specifically depicted inFIG. 1A, so long as the remote optical power supply 100 includes thelaser array 103 of multiple laser elements 103-1 through 103-N, witheach of the multiple laser elements 103-1 through 103-N operating togenerate laser light at a different one of N wavelengths. Also, itshould be understood that the configuration of the chip 111 as shown inFIG. 1C is provided by way of example. In various embodiments, theconfiguration of the chip 111 can vary from what is specificallydepicted in FIG. 1C, so long as the chip 111 includes the opticalwaveguides 121-1 through 121-M configured to extend past the pluralityof resonator structures 119-x-y.

FIG. 2 shows a transmission spectrum of a given resonator structure ofthe plurality of resonator structures 119-x-y, in accordance with someembodiments. The given resonator structure has multiple resonancewavelengths 1*λ₁, 2*λ₁, 3*λ₁, etc., that correspond to the modes of thegiven resonator structure. The wavelength range between spectrallyadjacent resonance wavelengths (between adjacent modes) of the givenresonator structure is a free spectral wavelength range (FSR) 201 of thegiven resonator structure. Each resonator structure in the plurality ofresonator structures 119-x-y has a respective FSR 201 and a respectiveresonance wavelength.

FIG. 3 shows that the plurality of resonator structures 119-x-y areconfigured so that each resonator structure in the plurality ofresonator structures 119-x-y has a different resonance wavelengthrelative to the other resonator structures in the plurality of resonatorstructures 119-x-y, in accordance with some embodiments. For example,resonator structure 119-x-1 has the resonance wavelength λ₁ and the FSR203-x-1. Resonator structure 119-x-2 has the resonance wavelength λ₂ andthe FSR 203-x-2. Resonator structure 119-x-3 has the resonancewavelength λ₃ and the FSR 203-x-3. Resonator structure 119-x-N has theresonance wavelength λ_(N) and the FSR 203-x-N.

As shown in FIG. 3, the plurality of resonator structures 119-x-y isconfigured so that the resonance wavelength of each resonator structurein the plurality of resonator structures 119-x-y is within one FSR 203of any one resonator structure of the plurality of resonator structures119-x-y. Therefore, a maximum difference in resonance wavelength betweenany two resonator structures in the plurality of resonator structures119-x-y is less than a minimum FSR of any resonator structure in theplurality of resonator structures 119-x-y. For example, if the FSR203-x-1 of the resonator structure 119-x-1 is considered to be theminimum FSR of any resonator structure in the plurality of resonatorstructures 119-x-y, then FIG. 3 shows that the maximum difference inresonance wavelength between any two resonator structures in theplurality of resonator structures 119-x-y (which corresponds toλ_(N)-λ₁) is less than the FSR 203-x-1 of the resonator structure119-x-1.

In some embodiments, the FSR of each resonator structure in theplurality of resonator structures 119-x-y is substantially equal, e.g.,within +/−10%. This is depicted in FIG. 3 where the FSR 203-x-1 of thefirst resonator structure 119-x-1 is substantially equal to the FSR203-x-2 of the second resonator structure 119-x-2, which issubstantially equal to the FSR 203-x-3 of the third resonator structure119-x-3, which is substantially equal to the FSR 203-x-N of the Nthresonator structure 119-x-N.

Also, in some embodiments, the difference in resonance wavelengthbetween any two resonator structures in the plurality of resonatorstructures 119-x-y is substantially equal to an integer multiple of afixed wavelength range WR. This is depicted in FIG. 3, where thedifference between the resonance wavelength λ₂ of the second resonatorstructure 119-x-2 and the resonance wavelength λ₁ of the first resonatorstructure 119-x-1 is substantially equal to 1*WR, and the differencebetween the resonance wavelength λ₃ of the third resonator structure119-x-3 and the resonance wavelength λ₁ of the first resonator structure119-x-1 is substantially equal to 2*WR, and the difference between theresonance wavelength λ_(N) of the Nth resonator structure 119-x-N andthe resonance wavelength λ₁ of the first resonator structure 119-x-1 issubstantially equal to (N−1)*WR. Also, in some embodiments, the fixedwavelength range WR is substantially equal to the free spectralwavelength range of a given one of the resonator structures of theplurality of resonator structures 119-x-y divided by the number (N) ofresonator structures in the plurality of resonator structures 119-x-y.For example, in FIG. 3, the fixed wavelength range WR is substantiallyequal to the FSR 203-x-1 of the first resonator structure of theplurality of resonator structures 119-x-y divided by N, where N is thenumber of resonator structures in the plurality of resonator structures119-x-y.

As shown in FIGS. 1A, 1B, and 1C, the laser array 103 includes aplurality of lasers 103-1 to 103-N optically connected to the pluralityof resonator structures 119-x-y within the chip 111. Each laser 103-1 to103-N is configured to generate continuous wave light having arespective wavelength (λ₁ to λ_(N)). The laser array 103 is specified tohave a central wavelength λ_(C). In some embodiments, the centralwavelength λ_(C) of the laser array 103 corresponds to a particularwavelength of continuous wave light generated by one of the plurality oflasers 103-1 to 103-N. However, in some embodiments, the centralwavelength λ_(C) of the laser array 103 does not correspond to aparticular wavelength of continuous wave light generated by any one ofthe plurality of lasers 103-1 to 103-N. In some embodiments, the centralwavelength λ_(C) of the laser array 103 is substantially equal toone-half of a difference between a maximum wavelength and a minimumwavelength generated by the laser array 103, i.e., substantially equalto (λ_(N)−λ₁)/2. In some embodiments, a variability of the centralwavelength λ_(C) of the laser array 103 is greater than a minimumdifference in resonance wavelength between any two spectrallyneighboring resonator structures in the plurality of resonatorstructures 119-x-y. The term spectrally neighboring resonator structuresmeans any two resonator structures within the plurality of resonatorstructures 119-x-y that have neighboring resonance wavelengths withinthe wavelength spectrum. For example, in FIG. 3, each of resonatorstructures 119-x-1 and 119-x-3 is a neighboring resonator structure ofthe resonator structure 119-x-2. The variability of the centralwavelength λ_(C) of the laser array 103 corresponds to a maximumallowable amount variation in the central wavelength λ_(C) of the laserarray 103 about a specified target wavelength λ_(T).

FIG. 4A shows an example transmission spectrum for a set of fourresonator structures 119-x-1 to 119-x-4, and a spectral positioning ofwavelengths (λ_(L1) to λ_(L4)) of continuous wave (CW) laser light asgenerated by the laser array 103 relative to the resonance wavelengths(λ₁ to λ₄) of the set of four resonator structures 119-x-1 to 119-x-4,in accordance with some embodiments. In the example of FIG. 4A, thecentral wavelength λ_(C) of the laser array 103 has an allowablevariability 401 relative to the specified target wavelength λ_(T) thatis greater than a minimum difference in resonance wavelength between anytwo spectrally neighboring resonator structures in the plurality ofresonator structures 119-x-y. It should be understood that as thecentral wavelength λ_(C) of the laser array 103 changes within theallowable variability 401, each of the wavelengths (λ_(L1) to λ_(L4)) ofcontinuous wave light generated by the laser array 103 correspondinglychanges.

FIG. 4A shows the spectral positioning of wavelengths (λ_(L1) to λ_(L4))of continuous wave laser light as generated by the laser array 103 tothe resonance wavelengths (λ₁ to λ₄) of the set of four resonatorstructures 119-x-1 to 119-x-4 when the central wavelength X_(C) of thelaser array 103 is substantially equal to the specified targetwavelength λ_(T). FIG. 4B shows the spectral positioning of wavelengths(λ_(L1) to λ_(L4)) of continuous wave laser light as generated by thelaser array 103 to the resonance wavelengths (λ₁ to λ₄) of the set offour resonator structures 119-x-1 to 119-x-4 when the central wavelengthλ_(C) of the laser array 103 is at a low end of the allowablevariability 401, in accordance with some embodiments. FIG. 4C shows thespectral positioning of wavelengths (λ_(L1) to λ_(L4)) of continuouswave laser light as generated by the laser array 103 to the resonancewavelengths (λ₁ to λ₄) of the set of four resonator structures 119-x-1to 119-x-4 when the central wavelength λ_(C) of the laser array 103 isat a high end of the allowable variability 401, in accordance with someembodiments.

In some embodiments, the variability 401 of the central wavelength λ_(C)of the laser array 103 is greater than two times the minimum differencein resonance wavelength between any two spectrally neighboring resonatorstructures in the plurality of resonator structures 119-x-y. In someembodiments, the variability 401 of the central wavelength λ_(C) of thelaser array 103 is greater than the free spectral wavelength range ofany resonator structure in the plurality of resonator structures119-x-y. For example, with reference to FIG. 4A, the variability of thecentral wavelength λ_(C) of the laser array 103 is greater than any oneof FSR 203-x-1, FSR 203-x-2, FSR 203-x-3, and FSR 203-x-4.

In view of the foregoing, an optical data communication system isdisclosed herein that includes an electronic/photonic device, e.g., chip111, for optical data communication, where the electronic/photonicdevice includes a plurality of resonator structures, e.g., 119-x-y. Theoptical data communication system also includes a laser array, e.g.,103. Each resonator structure in the plurality of resonator structureshas a respective free spectral wavelength range and a respectiveresonance wavelength. A maximum difference in resonance wavelengthbetween any two resonator structures in the plurality of resonatorstructures is less than a minimum free spectral wavelength range of anyresonator structure in the plurality of resonator structures. The laserarray includes a plurality of lasers, e.g., 103-1 to 103-N, opticallyconnected to the plurality of resonator structures. Each laser in theplurality of lasers is configured to generate continuous wave lighthaving a respective wavelength. The laser array has a centralwavelength. A variability of the central wavelength is greater than aminimum difference in resonance wavelength between any two spectrallyneighboring resonator structures in the plurality of resonatorstructures, e.g., 119-x-y.

In some embodiments, the laser array 103 is configured so as to generatecontinuous wave (CW) light at different wavelengths that substantiallyalign with the different resonance wavelengths of the resonatorstructures in the plurality of resonator structures 119-x-y. In someembodiments, a difference in continuous wave light wavelength betweenspectrally neighboring lasers in the laser array 103 is substantiallyequal to a difference in resonance wavelength between correspondingspectrally neighboring resonator structures in the plurality ofresonator structures 119-x-y. In some embodiments, however, one or moreof the different wavelength(s) of the continuous wave light generated bythe laser array 103 does not sufficiently align with the correspondingresonance wavelength(s) of the resonator structure(s) in the pluralityof resonator structures 119-x-y. To manage this, each resonatorstructure in the plurality of resonator structures 119-x-y is configuredto have independent resonance wavelength tuning.

In some embodiments, each of the transmit macros 115-1 to 115-M includesa tuning control system that has a tuning connection to each resonatorstructure in the plurality of resonator structures 119-x-y in thecorresponding transmit macro. The tuning control system is configured toshift the resonance wavelength of each resonator structure in theplurality of resonator structures 119-x-y to substantially align with anearest wavelength of continuous wave light generated by the laser array103. In some embodiments, a plurality of heaters is respectivelydisposed proximate to the plurality of resonator structures 119-x-y inthe transmit macros 115-1 to 115-M. Each of the plurality of heaters iselectrically connected to the tuning control system in the correspondingtransmit macro. Also, each of the plurality of heaters is independentlycontrollable by the tuning control system in the corresponding transmitmacro. In some embodiments, the tuning control system in the transmitmacro is configured to use electrical current to shift the resonancewavelength of each resonator structure in the plurality of resonatorstructures 119-x-y to substantially align with a nearest wavelength ofcontinuous wave light generated by the laser array 103.

FIG. 5 shows a flowchart of a method for configuring an optical datacommunication system, in accordance with some embodiments. The methodincludes an operation 501 for having an electronic/photonic device,e.g., chip 111, for optical data communication that includes a pluralityof resonator structures, e.g., resonator structures 119-x-y. Eachresonator structure in the plurality of resonator structures has arespective free spectral wavelength range and a respective resonancewavelength. A maximum difference in resonance wavelength between any tworesonator structures in the plurality of resonator structures is lessthan a minimum free spectral wavelength range of any resonator structurein the plurality of resonator structures. The method also includes anoperation 503 for optically connecting a laser array, e.g., laser array103, to the electronic/photonic device. The laser array includes aplurality of lasers, e.g., lasers 103-1 to 103-N, optically connected tothe plurality of resonator structures. Each laser in the plurality oflasers is configured to generate continuous wave light having arespective wavelength, e.g., λ₁ to λ_(N). The laser array has a centralwavelength e.g., λ_(C). A variability of the central wavelength isgreater than a minimum difference in resonance wavelength between anytwo spectrally neighboring resonator structures in the plurality ofresonator structures. In some embodiments, the laser array is physicallyseparate from a device that includes the plurality of resonatorstructures.

In some embodiments, the variability of the central wavelength of thelaser array corresponds to a maximum allowable amount variation in thecentral wavelength of the laser array about a specified targetwavelength. In some embodiments, a difference in continuous wave lightwavelength between spectrally neighboring lasers in the laser array issubstantially equal to a difference in resonance wavelength betweencorresponding spectrally neighboring resonator structures in theplurality of resonator structures. In some embodiments, the freespectral wavelength range of each resonator structure in the pluralityof resonator structures is substantially equal. In some embodiments, thedifference in resonance wavelength between any two resonator structuresin the plurality of resonator structures is substantially equal to aninteger multiple of a fixed wavelength range. In some embodiments, thefixed wavelength range is equal to the free spectral wavelength rangedivided by a number of resonant structures in the plurality of resonantstructures.

In some embodiments, the variability of the central wavelength of thelaser array is greater than two times the minimum difference inresonance wavelength between any two resonator structures in theplurality of resonator structures. In some embodiments, the variabilityof the central wavelength of the laser array is greater than the freespectral wavelength range of any resonator structure in the plurality ofresonator structures. In some embodiments, each resonator structure ofthe plurality of resonator structures is configured to have asubstantially same shape and size, e.g., within +/−20%. In someembodiments, different resonator structures in the plurality ofresonator structures are configured to have different shapes, differentsizes, or both different shapes and different sizes. In someembodiments, each resonator structure in the plurality of resonatorstructures is substantially ring-shaped or disc-shaped. In someembodiments, the laser array is physically separate from a device thatincludes the plurality of resonator structures. In some embodiments,each resonator structure in the plurality of resonator structure is amicroring resonator that has an outer diameter of less than 10micrometers.

In some embodiments, the method includes operating a tuning controlsystem to independently control the resonance wavelength of eachresonator structure of the plurality of resonator structures. In someembodiments, the method includes operating a tuning control system toshift the resonance wavelength of each resonator structure of theplurality of resonator structures to substantially align with a nearestwavelength of continuous wave light generated by the laser array. Insome embodiments, the method includes operating a tuning control systemto control a plurality of heaters respectively disposed proximate to theplurality of resonator structures, where each heater of the plurality ofheaters is independently controlled by the tuning control system toshift the resonance wavelength of each resonator structure of theplurality of resonator structures to substantially align with a nearestwavelength of continuous wave light generated by the laser array.

The foregoing description of the embodiments has been provided forpurposes of illustration and description, and is not intended to beexhaustive or limiting. Individual elements or features of a particularembodiment are generally not limited to that particular embodiment, but,where applicable, are interchangeable and can be used in a selectedembodiment, even if not specifically shown or described. In this manner,one or more features from one or more embodiments disclosed herein canbe combined with one or more features from one or more other embodimentsdisclosed herein to form another embodiment that is not explicitlydisclosed herein, but rather that is implicitly disclosed herein. Thisother embodiment may also be varied in many ways. Such embodimentvariations are not to be regarded as a departure from the disclosureherein, and all such embodiment variations and modifications areintended to be included within the scope of the disclosure providedherein.

Although some method operations may be described in a specific orderherein, it should be understood that other housekeeping operations maybe performed in between method operations, and/or method operations maybe adjusted so that they occur at slightly different times orsimultaneously or may be distributed in a system which allows theoccurrence of the processing operations at various intervals associatedwith the processing, as long as the processing of the method operationsare performed in a manner that provides for successful implementation ofthe method.

Although the foregoing embodiments have been described in some detailfor purposes of clarity of understanding, it will be apparent thatcertain changes and modifications can be practiced within the scope ofthe appended claims. Accordingly, the embodiments disclosed herein areto be considered as illustrative and not restrictive, and are thereforenot to be limited to just the details given herein, but may be modifiedwithin the scope and equivalents of the appended claims.

What is claimed is:
 1. An optical data communication system, comprising:a plurality of resonator structures, each resonator structure in theplurality of resonator structures having a respective free spectralwavelength range and a respective resonance wavelength, wherein amaximum difference in resonance wavelength between any two resonatorstructures in the plurality of resonator structures is less than aminimum free spectral wavelength range of any resonator structure in theplurality of resonator structures; and a laser array including aplurality of lasers optically connected to the plurality of resonatorstructures, each laser in the plurality of lasers configured to generatecontinuous wave light having a respective wavelength, the laser arrayhaving a central wavelength, wherein a variability of the centralwavelength is greater than a minimum difference in resonance wavelengthbetween any two spectrally neighboring resonator structures in theplurality of resonator structures.
 2. The optical data communicationsystem as recited in claim 1, wherein the variability of the centralwavelength of the laser array corresponds to a maximum allowable amountvariation in the central wavelength of the laser array about a specifiedtarget wavelength.
 3. The optical data communication system as recitedin claim 1, wherein a difference in continuous wave light wavelengthbetween spectrally neighboring lasers in the laser array issubstantially equal to a difference in resonance wavelength betweencorresponding spectrally neighboring resonator structures in theplurality of resonator structures.
 4. The optical data communicationsystem as recited in claim 1, wherein the free spectral wavelength rangeof each resonator structure in the plurality of resonator structures issubstantially equal.
 5. The optical data communication system as recitedin claim 1, wherein the difference in resonance wavelength between anytwo resonator structures in the plurality of resonator structures issubstantially equal to an integer multiple of a fixed wavelength range.6. The optical data communication system as recited in claim 5, whereinthe fixed wavelength range is equal to the free spectral wavelengthrange divided by a number of resonant structures in the plurality ofresonant structures.
 7. The optical data communication system as recitedin claim 1, wherein the variability of the central wavelength of thelaser array is greater than two times the minimum difference inresonance wavelength between any two spectrally neighboring resonatorstructures in the plurality of resonator structures.
 8. The optical datacommunication system as recited in claim 1, wherein the variability ofthe central wavelength of the laser array is greater than the freespectral wavelength range of any resonator structure in the plurality ofresonator structures.
 9. The optical data communication system asrecited in claim 1, wherein each resonator structure in the plurality ofresonator structures is configured to have a substantially same shapeand size.
 10. The optical data communication system as recited in claim1, wherein different resonator structures in the plurality of resonatorstructures are configured to have different shapes, different sizes, orboth different shapes and different sizes.
 11. The optical datacommunication system as recited in claim 1, wherein each resonatorstructure in the plurality of resonator structures is substantiallyring-shaped or disc-shaped.
 12. The optical data communication system asrecited in claim 1, wherein the laser array is physically separate froma device that includes the plurality of resonator structures.
 13. Theoptical data communication system as recited in claim 1, wherein eachresonator structure in the plurality of resonator structures isconfigured to have independent resonance wavelength tuning.
 14. Theoptical data communication system as recited in claim 1, furthercomprising: a tuning control system having a tuning connection to eachresonator structure in the plurality of resonator structures, the tuningcontrol system configured to shift the resonance wavelength of eachresonator structure in the plurality of resonator structures tosubstantially align with a nearest wavelength of continuous wave lightgenerated by the laser array.
 15. The optical data communication systemas recited in claim 14, further comprising: a plurality of heatersrespectively disposed proximate to the plurality of resonatorstructures, each of the plurality of heaters electrically connected tothe tuning control system and independently controllable by the tuningcontrol system.
 16. A method for configuring an optical datacommunication system, comprising: having an electronic/photonic devicefor optical data communication that includes a plurality of resonatorstructures, each resonator structure in the plurality of resonatorstructures having a respective free spectral wavelength range and arespective resonance wavelength, wherein a maximum difference inresonance wavelength between any two resonator structures in theplurality of resonator structures is less than a minimum free spectralwavelength range of any resonator structure in the plurality ofresonator structures; and optically connecting a laser array to theelectronic/photonic device, the laser array including a plurality oflasers optically connected to the plurality of resonator structures,each laser in the plurality of lasers configured to generate continuouswave light having a respective wavelength, the laser array having acentral wavelength, wherein a variability of the central wavelength isgreater than a minimum difference in resonance wavelength between anytwo spectrally neighboring resonator structures in the plurality ofresonator structures.
 17. The method as recited in claim 16, wherein thevariability of the central wavelength of the laser array corresponds toa maximum allowable amount variation in the central wavelength of thelaser array about a specified target wavelength.
 18. The method asrecited in claim 16, wherein a difference in continuous wave lightwavelength between spectrally neighboring lasers in the laser array issubstantially equal to a difference in resonance wavelength betweencorresponding spectrally neighboring resonator structures in theplurality of resonator structures.
 19. The method as recited in claim16, wherein the free spectral wavelength range of each resonatorstructure in the plurality of resonator structures is substantiallyequal.
 20. The method as recited in claim 16, wherein the difference inresonance wavelength between any two resonator structures in theplurality of resonator structures is substantially equal to an integermultiple of a fixed wavelength range.
 21. The method as recited in claim20, wherein the fixed wavelength range is equal to the free spectralwavelength range divided by a number of resonant structures in theplurality of resonant structures.
 22. The method as recited in claim 16,wherein the variability of the central wavelength of the laser array isgreater than two times the minimum difference in resonance wavelengthbetween any two resonator structures in the plurality of resonatorstructures.
 23. The method as recited in claim 16, wherein thevariability of the central wavelength of the laser array is greater thanthe free spectral wavelength range of any resonator structure in theplurality of resonator structures.
 24. The method as recited in claim16, wherein each resonator structure of the plurality of resonatorstructures is configured to have a substantially same shape and size.25. The method as recited in claim 16, wherein different resonatorstructures in the plurality of resonator structures are configured tohave different shapes, different sizes, or both different shapes anddifferent sizes.
 26. The method as recited in claim 16, wherein eachresonator structure in the plurality of resonator structures issubstantially ring-shaped or disc-shaped.
 27. The method as recited inclaim 16, wherein the laser array is physically separate from a devicethat includes the plurality of resonator structures.
 28. The method asrecited in claim 16, further comprising: operating a tuning controlsystem to independently control the resonance wavelength of eachresonator structure of the plurality of resonator structures.
 29. Themethod as recited in claim 16, further comprising: operating a tuningcontrol system to shift the resonance wavelength of each resonatorstructure of the plurality of resonator structures to substantiallyalign with a nearest wavelength of continuous wave light generated bythe laser array.
 30. The method as recited in claim 16, furthercomprising: operating a tuning control system to control a plurality ofheaters respectively disposed proximate to the plurality of resonatorstructures, each heater of the plurality of heaters independentlycontrolled by the tuning control system to shift the resonancewavelength of each resonator structure of the plurality of resonatorstructures to substantially align with a nearest wavelength ofcontinuous wave light generated by the laser array.